The first video games were played on massive computers connected to vector displays. Several generations of video game consoles connectable to a television were later developed having interchangeable discs or cartridges. Games on video game consoles could be played amongst users within an immediate vicinity. Online games are now played on various types of computing devices. An online game is a game that is either partially or primarily played by one or more users who communicate through the Internet or other data communications computer network. Conventional online game sessions are hosted or managed by a game server, which is typically a dedicated computer managed by the game publisher or other company. Users typically initiate online game sessions by directly accessing a web page of a third-part game server. Alternatively, applications (“apps”) or console games may communicate with a server to exchange score information, game updates, etc.
Over the last several years, social networks have become a useful way to connect with acquaintances or businesses, e.g., to communicate. Social networks may have a social graph that identifies interrelationships between users. A subset of the users of a social network may be friends, in which case the social graph may have particular connections between nodes of the graph representing the users. Social network users, e.g., friends or other users, can be involved in various online conversations, e.g., by posting content on a friend's online “wall” or a company's online “page.” Walls, pages, or other shareable areas of the social network (e.g., newsfeed, timeline, etc.) enable users to post and see various content, e.g., text, photographs, videos, etc. Some social networks also have a messaging app that enables two or more users to communicate with each other, e.g., by exchanging messages. Because social networks are now used by many millions (even billions) of users daily, they have the potential to offer game publishers tremendous opportunity to expand their online game presence in meaningful ways.